Centering device



Mar.13,1923. 1,448,528.

y f R. P. ELLIOTT.

CENTERING. DEVICE.

' FILED DEC. l1, 1920.

Patented Mar. 13, 1923.

narran stares httc- :@FFQE.

PATENT RICHARD r. ELLIOTT, or LEXINGTON, Massaciiusnr'rs.

CENTERING DEVICE.

Application filed December 11, 1920.

tion, `like characters on the drawingslrepresenting like parts.

My invention relates to a centering device for centering one or more ring-shaped articles by their interior surfaces.

The objects of my invention are topro.- vide a device which may be inserted inside one or more articles which are ring-shaped, the holes of which may or may not be true circles, and which may or may not be of the same diameters, to bring and maintain the interior'surfaces of saidrings to approximately a common axis until said articles can be secured in such position to be machined. y Y

It is often necessary to machine ringshaped vcastings on their interior` surfaces. Such castings are more or less rough, of unequal diameters, and out ofl round. In such cases it is practically impossible to center and hold a. number of such castings byv their outside circumferential surfaces and bring their inside surfaces to a common rotative axis. l y

It is a common expedient to hold ringshaped articles, either rough or finished, by side pressure.

Usually enough 'extra material in the ring-like object is provided to make up for the inequalities in diameter and out of roundness and the inability to bring such surfaces to an approximate common diam* eter.v n

Mydevice is ca-pable of overcoming such difficulties, `and in its preferred form is provided with av plurality of expanding memberswhieh are provided with yielding means for engaging theint'erioi surfaces of the ,ring-like objects to be brought to a common axis.

Inthe drawings-.- v Fi-gure'l is aside viewk of` a centering deviceembodying the invention in its expanded position.; Figure 2 a longitudinal 'sectionalviewrof thesdevice shown in Fig. 1; Figure 3 Van end v iewtaken from the left Serial No. 430,000.

hand end of Figure 1; and Figure t is a cross section through line 4-4 Figure 2,.

The embodiment of my invention shown herein consists of the 'straight cylindrical arbor 10 having mounted thereon and re.- movably secured thereto the spider 11 having live radiating arms 12, provided ywith vslots 13, and the pivots 14, to which -are pivoted the five links 15 which are provided with v the pivots 16, by means vof which they are pivoted to radially movable expanding members or bars 17. The bars 17 vare provided with tapering inner surfaces 18 adapted to contact with the 'sliding tapering member 19, which has formed in its periphery at one end grooves 2O to receive the inwardly projecting points or lugs 21 on'V the bars 17 which fit in and slide in theslots 2Q. To maintain the bars 17 in contact lwithgthe sliding bar 19 there are provided coil springs 22 and 23 which pass through the holes 24 and 25 formed in said bars, the ends of the springs 22 andA 23 being brought together and fastened so that theirV action willy hold the bars 17 in contact'with theslidingvmem ber 19. As a means Vof supporting the` centering device, I provide t one of its ends to fit into a suitable recess in the holding chuckwhich may be `used in conjunction with my device.

In using my device `it is customary to rovide a hole true with the rotative axis of the chuck to receive the end 30 of the arborv 10, and to support the other end of the arbor 10 in such manner that the axis of said arbor will coincide and be in f a straight line with the rotative axis of the arbor or whatever' it is thaty supports the chuck, not shown, which holds the articles to be centered. Suitable yielding or elastic means may be secured to the bars 17. In the embodiment of my invention I prefer. to use high grade rubber strips 81. These strips are inserted in groovesinthe outside edges of the members- 17 'and are machined by suitable means,such as grinding, so that they will be exactly concentric with thevaxis of the arbor 10andrun true. therewith.

While in this` embodiment I have l. described a rubber strip, I find thatkagood hard felt or similar substance mayV beused; also that I may use a tightly coiled lspring inserted .in ksaid grooveso 'asy to leaye` the major portion of the body of said spring e portion .30 on j Thereafter, the member 19 is pushed to the left, ais-shown in Figure 2, to expand or push the bars 17 radially-outward to conv tact with the objectsto be centered. If two of the objects of different diametershappen -to `be located vside by side, -the one of the smallerfdiameter will be pressed into the yielding sur-faces 31, while the yielding surface in contact with the next article, which is larger, will remain in its normal position and will touch suchlarger article andy center it approximatell concentric with the axisl of the shaft 10. iihere there are lumps yor projections on the interior surfaces, provided they do not'come between the members 31 and yhappen to contact with any one of the yielding surfaces 31, they are embedded in such yielding surface in such manner as to" allow such article to be ad'-l justed and centered vto bring its interior surfaceto ka common axis, or approximating'the axis of the arbor 10. lVVhen all such articles which it is desired to center are brought to a common axis, they are secured in such position by side pressure, uwhereupon the centering device is removed byA taking the pressure off the right hand endy of the member 19. to allow the spring 32 to move said member 19 to the right and permit the arms 17 to moveinwardly and awayfrom the interior of the surface of the articles to be centered, and thereafter to be taken out vso as to permit of the desired machining operation, whereby the inner circumferences of the hollow objects, such as rings, may be ground or otherwise-treated to provide them with inner circumferences of the same diameter.` j i From the above description, it will be observed that the centering device is provided with'yielding members which engages the inner ysurface of the ring-shaped object or objects, and yields locallyU under the influence of said objects, and one embodiment of the invention is herein shown but it is not desired to limit the invention to the particular construction shown. i

What I claim vis-" 1. In a centeringldevice of the character described, in combination, a sliding taperying member rprovided with longitudinally extended grooves inits outer surface, taper- -ing bars engaging said members and-having portions :Eittedinto said grooves, said tapering bars lbeing movable radially by longitudinal movement of said tapering member, yielding means for maintaining said tapering bars in contact with said tapering member, and'yielding members carried by said tapering ba-rs and arranged to engage the inner surface of' the object to be centered. 2. In a centering device of thev character described, iii combination, a longitudinally movable member, a radially movable member (io-operating Awith said longitudinally movable member to bev moved thereby into engagement with the ring-like object to `be centered, and a yielding membery arranged with relation to said radially movable member to be engaged thereby'with the inner surface of said ring-like object.

3. In a centering device of the character described, in combination, a yielding member for engagement withk the inner surface of aring-lilre object to be` centered, and means for moving said vyielding member radially with relation to said ring-like object.

4. In al centering device of the character described,.a member for engaging'the inner surface of a ring-like objectftobe centered and capable of yielding locally to enable a plurality of ring-like objects of different diameters to bev centered with relation to a .common axis, and means; for movingsaid member -with relationl to objectpy i 5.`In a centering device ofthe character described, an arbor, a tapering member mounted thereon, expanding members provided withy tapered inner surfaces IVin engagement withjsaid tapering member, one of said members-being movable with relation to the other toy effect movement of the expanding members radially n with vrelation n c n I said ring-like ico i to said arbor, and yielding members carried 7 by said expanding members and arranged substantially concentric with said arbor.

6. In a centering device of the character describedin combination, an arbor, an expanding member provided withan outer surface for engagement with the inner surface of a ring-likeobject and capable of yieldingunder the influence of said yringlilze object to permit the. latter to vbe substantially centered with relation to said arbor, and means for moving said expanding member with relation to said object.

7, In a centering device of the character described, in combination, an arbor, a tapering member mounted on said arbor to move 4 longitudinally thereon, 'a plurality oftapering bars! co-operating with said tapering member and movable radially, means for movably connecting said tapering barswith said arbor, yielding members carriedv by said l tapering bars at their outer surfaces, a

spring mounted on said arbor for moving i said tapering member in one'direction, 'and means for moving the tapering bars radially iso toward said shaft when said tapering member is moved longitudinally on said arbor by said spring.

8. In a centering device of the character described, a member for engaging a surface of a ring like object to be centered and capable of yielding locally to enable a plurality of ring like objects of different diameters to be centered with relation to a common axis, and means for moving said member With relation to said ring like object.

9. In a device for centering a plurality of ring like objects of diierent diameters With relation to a common axis, a plurality of yielding members arranged axially with relation to the ring like objects to engage a surface thereof and permit the said objects to be individually centered With relation to said common axis, supporting members for said yielding members, and means for moving said supporting membersyvvith relation to .said ring like objects and said common axis.

In testimony whereof, I have signed my name to this specification.

RICHARD P. ELLIOTT. 

